Hypertension Flashcards
Distribution of blood pressure
Normal distribution
Problems with hypertension management
Isn’t discrete population groups of ‘hypertension’ and ‘not hypertension’
Most asymptomatic, treatments have side effects
BP can be adjusted by producing changes in the following variables =
- Cardiac output/stroke volume
- Blood volume
- HR
- Resistance to blood flow
2 types of receptors that input into CVS
- Baroreceptors
2. Chemoreceptors
Baroreceptors found in =
Carotid sinus
Aortic arch
Right atrium
Chemoreceptors found in =
Carotid bodies
Aortic bodies
Systems which control BP
Cardiovascular system
Renal system
Effects of angiotensin II
Vasoconstriction
Aldosterone release
Where is aldosterone released from?
Adrenal cortex
Effects of aldosterone
Increase Na+/H2O retention
Effects of adrenaline and noradrenaline =
Increase HR
Increase contractility
Vasoconstriction
AHD effects =
Retain H2O
ANP stands for
Atrial natriuretic peptide
ANP is released from
Atria
Effects of ANP =
Lowers flood pressure. Vasodilation, stimulating kidneys to secrete more H2O and Na+
NO is released by
Endothelial cells
NO causes
vasodilation
Effects of nicotine =
Increase BP, stimulate sympathetic neurones
Effects of alcohol =
Lowers BP by inhibiting ADH
90-95% of patients with hypertension have
Essential/primary hypertension
Early stages of essential hypertension =
Higher than normal cardiac output/blood volume
Chronic stages of essential hypertension =
Blood volumes/cardiac output normal.
Increased systemic vascular resistance
What causes increased systemic vascular resistance in chronic essential hypertension?
Thickening of vessels
Reduced lumen diameter
Increased vascular tone
Reduced NO/reduced sensitivity to NO
5-10% of hypertension cases are due to
Secondary hypertension
Secondary hypertension often has what kind of cause?
Endocrine
Renal
Ex of renal causes of hypertension
Renal artery stenosis
Chronic renal disease
Renal artery stenosis =
Kidneys are hypoperfused
RAAS system activated
Increased blood volumes, cardiac output, resistance
Chronic renal disease is caused by
Processes which damage the kidney (e.g. diabetic nephropathy, glomerulonephritis)
Chronic renal disease =
Reduces Na+/H2O excretion
Increased renin release
Examples of endocrine causes of hypertension
Conns syndrome
Phaeochromocytoma
Conns syndrome also known as
primary hyperaldosteronism
Causes of Conns syndrome
Adrenal tumors
Hyperplasia
What happens in Conns syndrome?
Increased aldosterone
Na+ and H2) retention
Decreased renin and K+
What is decreased in Conns syndrome?
Renin:aldosterone
K+
A phaeochromocytoma is a
Neuroendocrine tumour of the adrenal medulla
A phaeochromocytoma secretes
Catecholamines
Effects of phaeochromocytoma =
Alpha mediated vasoconstriction
Beta mediated cardiac stimulation
How to diagnose phaeochromocytoma
Diagnose 24 hr urinary catecholamines
What is a coarctation of the aorta?
Aortic narrowing
What causes coarctation of the aorta?
Congential condition - aorta narrowed where ductus arteriosus inserts
What occurs in coarctation of the aorta?
Kidneys are hypoperfused RAAS activated Upper body hypertension Lower body normotension Radialfemoral delay
Radiofemoral delay occurs in what condition?
Coarctation of the aorta
Other causes of secondary hypertension:
Cushings Thyroid Pregnancy Alcohol Liquorice
How does liquorice cause hypertension?
Inhibits enzyme which forms cortisone from cortisol - cortisol acts like aldosterone
What can happen to the eye in hypertension?
Retinopathy/pizza pie
What in the eye can be a sign of hypertension?
Papilloedema
What is accelerated hypertension?
A recent significant elevation over baseline blood pressure which is associated with organ damage
What does papilloedema indicate?
Raised ICP
What happens to the brain in accelerated hypertension?
Goes over upper limit of autoregulation - arterioles dilate - hyperperfusion - cerebral oedema - hypertensive encepalopathy
